Methodology And Application For The Control Of Edge Drop Effect Of Cold Rolling Steel

Edge drop,as one of the key factors that determine the quality of cold-rolling silicon steel sheets,has substantially constrained the efficiency and cost-effectiveness of silicon steel production.The major cause of the edge drop effect is in the cold-rolling process,where the uneven distribution of rolling forces creates less steel formation at the edges than in the center,resulting in reduction of thickness at the edges.To avoid the edge drop effect,re-design of work roll shape is required.When re-designing the roll shape,we should analyze the control force for edge dropping,resistance of deviation,and wearing effect of the rolls.In this paper,the shape of the existing work rolls used in a silicon steel manufacturer was analyzed,and effects such as edge drop,rolling deviation and wearing were found.This paper tries to address these effects by proposing new methodologies to re-design and improve the work roll shape.For the analysis,diagonal straight curve,quadratic curve,cubic curve and sinusoidal curve,which were commonly used for the shape of existing work roll,were studied and the effects of edge dropping,rolling deviation and wearing were compared.A new type of curve that combines both short and diagonal straight lines was identified to be ideal design for the work rolls.Detailed design of the new type was achieved by simulating the work roll shifting effect with finite element analysis.The result was shown in a shifting v.s.efficiency curve,which was used to guide the on-site manufacturing to deliver improved quality of the product.